<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
</head>

<body>
<script>
  arr = [
    [1,2,3,4],
    ['a','b'],
    ['一','二','三','四']
  ];
  for(var i=0;i<arr.length;i++){
	for(var j=0;j<arr[i].length;j++){
	  document.body.innerHTML += arr[i][j];
	  // alert(arr[i][j]);
    }
   }

</script>
</body>
</html>
